Royo Julie, Orset Thomas, Catani Marco, Pouget Pierre, Thiebaut de Schotten Michel
Brain Connectivity and Behaviour Laboratory, Paris 75013, France
Sorbonne University, Inserm U1127, CNRS UMR7225, UM75, ICM, Movement Investigation and Therapeutics Team, Paris 75013, France.
J Neurosci. 2025 Aug 13;45(33):e1646242025. doi: 10.1523/JNEUROSCI.1646-24.2025.
The dynamics of social dominance play a significant role in regulating access to resources and influencing reproductive success and survival in nonhuman primates. These dynamics are based on aggressive and submissive interactions that create distinct, hierarchically organized social structures. In humans, whose social behavior is similarly organized, the use of brain imaging based on tractography has identified key neuronal networks of the limbic system underlying social behavior. Among them, the uncinate fasciculus and the cingulum bundle have been associated with aggression and some disorders such as psychopathy. In this study, we have used advanced tractography to study the anatomy of connections underlying social dominance in a colony of 15 female squirrel monkeys (). We correlated the biostructural properties of the uncinate fasciculus and cingulum with behavioral hierarchy measures while controlling for factors such as age, weight, handedness, brain size, and hormonal influences. The fornix, a limbic connection involved in memory, was also included as the control tract. Our findings indicate a significant correlation between the integrity of the right uncinate fasciculus and social dominance measures, including normalized David's scores, aggressive behaviors, and submissive behaviors. Trends observed in the left uncinate fasciculus hint at potential bilateral involvement with a right hemispheric lateralization. These results are consistent with human studies linking the uncinate fasciculus to social aggression and disorders, suggesting an evolutionary continuity in the neuroanatomical substrates of social dominance back to at least 35 million years.
社会等级动态在调节非人类灵长类动物获取资源以及影响其繁殖成功率和生存方面发挥着重要作用。这些动态基于攻击性和顺从性互动，形成了独特的、层次分明的社会结构。在社会行为组织方式类似的人类中，基于纤维束成像的脑成像技术已确定了社会行为背后边缘系统的关键神经元网络。其中，钩状束和扣带束与攻击性及某些疾病（如精神病态）有关。在本研究中，我们使用先进的纤维束成像技术研究了15只雌性松鼠猴群体中社会等级背后的连接解剖结构。我们在控制年龄、体重、利手、脑容量和激素影响等因素的同时，将钩状束和扣带束的生物结构特性与行为等级测量结果进行了关联。穹窿，一种参与记忆的边缘连接，也被作为对照纤维束纳入研究。我们的研究结果表明，右侧钩状束的完整性与社会等级测量结果之间存在显著相关性，包括标准化的大卫分数、攻击性行为和顺从性行为。在左侧钩状束中观察到的趋势暗示可能存在双侧参与且右侧半球占优势。这些结果与将钩状束与社会攻击和疾病联系起来的人类研究一致，表明社会等级的神经解剖学基础至少在3500万年前就存在进化连续性。
